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The purpose of this paper is to present a solution strategy for the analysis of cable networks which includes an extension to the force density method (FDM) in an attempt to support cable elements when they become slack. The ability to handle slack cable elements in the analysis is particularly important especially in cases where the original cable lengths are predefined, i.e. the cable structure has already been constructed, and there is a need for further analysis to account for additional loading such as wind. The solution strategy is implemented in a software application.

The development of the software required the implementation of the FDM for the analysis of cable networks and its extension to handle constraints. The implemented constraints included the ability to preserve the length in the stressed or the unstressed state of predefined cable elements. In addition, cable statics are incorporated with the development of the cable equation and its modification to be able to be handled by the FDM .

The implementation of the solution strategy is presented through examples using the software which has been developed for these purposes.

The results suggest that for cable networks spanning large distances or cable elements with considerable self-weight the neglect of the cable slackening effects is not always conservative.

Pediatric disorders, such as cerebral palsy and stroke, can result in thumb-in-palm deformity greatly limiting hand function. This not only limits children's ability to perform activities of daily living but also limits important motor skill development. Specifically, the isolated orthosis for thumb actuation (IOTA) is 2 degrees of freedom (DOF) thumb exoskeleton that can actuate the carpometacarpal (CMC) and metacarpophalangeal (MCP) joints through ranges of motion required for activities of daily living. The paper aims to discuss these issues.

IOTA consists of a lightweight hand-mounted mechanism that can be secured and aligned to individual wearers. The mechanism is actuated via flexible cables that connect to a portable control box. Embedded encoders and bend sensors monitor the 2 DOF of the thumb and flexion/extension of the wrist. A linear force characterization was performed to test the mechanical efficiency of the cable-drive transmission and the output torque at the exoskeletal CMC and MCP joints was measured.

Using this platform, a number of control modes can be implemented that will enable the device to be controlled by a patient to assist with opposition grasp and fine motor control. Linear force and torque studies showed a maximum efficiency of 44 percent, resulting in a torque of 2.39±1.06 in.-lbf and 0.69±0.31 in.-lbf at the CMC and MCP joints, respectively.

The authors envision this at-home device augmenting the current in-clinic and at-home therapy, enabling telerehabilitation protocols.

This paper presents the design and characterization of a novel device specifically designed for pediatric grasp telerehabilitation to facilitate improved functionality and somatosensory learning.

This paper aims to present a reconfiguration strategy for actuated tensegrity structures. The main idea is to use the infinitesimal mechanisms of the structure to generate a path along which the tensegrity can change its shape while maintaining the equilibrium.

Combining the force density method with a marching procedure, the solution to the equilibrium problem is given by a set of differential equations. Beginning from an initial stable position, the algorithm calculates a small displacement until a new stable configuration is reached, and recurrently repeats the process during a given interval of time.

By means of three numerical simulations and their respective experimental example, the efficacy of this algorithm for reconfiguring the well-known three-bar tensegrity prism along different directions is shown. The proposed method shows efficiency only for small changes of string length. Further work should consider the application of this method to more complex tensegrity structures.

The advantage of this reconfiguration method is its simplicity for finding new stable positions for tensegrity structures, and the fact that it doesn’t need the information of the material of the structure for the computations.

Instantaneous unloading with equal force is usually used to simulate the sudden failure of cables. This simulation method with equivalent force requires obtaining the magnitude and direction of the force for the failed cable in the normal state. It is difficult, however, to determine the magnitude or direction of the equivalent force when the shape of the cable is complex (space curve). This model of equivalent force may be difficult to establish. Thus, a numerical simulation method, the instantaneous temperature rise method, was proposed to address the dynamic response caused by failures of the cables with complex structural form.

This method can instantly reduce the cable force to zero through the instantaneous temperature rise process of the cable. Combined with theoretical formula and finite element model, the numerical calculation principle and two key parameters (temperature rise value and temperature rise time) of this method were detailed. The validity of this approach was verified by comparing it with equivalent force models. Two cable-net case with saddle curved surfaces were presented. Their static failure behaviors were compared with the dynamic failure behaviors calculated by this method.

This simulation method can effectively address the structural dynamic response caused by cable failure and may be applied to all cable structures.

An instantaneous temperature rise method (ITRM) is proposed and verified. Its calculation theory is detailed. Two key parameters, temperature rise value and temperature rise time, of this method are discussed and the corresponding reference values are recommended.

The purpose of this paper is to propose an accurate and efficient numerical method for determining the dynamic responses of a tensegrity structure consisting of bars, which can work under both compression and tension, and cables, which cannot work under compression.

An accurate time-domain solution is obtained by using the precise integration method when there is no cable slackening or tightening, and the Newton–Raphson scheme is used to determine the time at which the cables tighten or slacken.

Responses of a tensegrity structure under harmonic excitations are given to demonstrate the efficiency and accuracy of the proposed method. The validation shows that the proposed method has higher accuracy and computational efficiency than the Runge–Kutta method. Because the cables of the tensegrity structure might be tense or slack, its dynamic behaviors will exhibit stable periodicity, multi-periodicity, quasi-periodicity and chaos under different amplitudes and frequencies of excitation.

The steady state response of a tensegrity structure can be obtained efficiently and accurately by the proposed method. Based on bifurcation theory, the Poincaré section and phase space trajectory, multi-periodic vibration, quasi-periodic vibration and chaotic vibration of the tensegrity structures are predicted accurately.

As cable and satellite industry undergoes transformation in the 21st century with the onslaught of innovation-driven changes, it is important to know which company is doing better and which company is falling behind. This study compares the relative performance of eight cable companies using three factors: operating expense for every dollar of operating revenue, earnings before interest, taxes, depreciation, and amortization, and return on assets. We also evaluate the performance of each firm against itself for the period 2010–2013 to see if they show improvement or deterioration in operating efficiency.

Planes and the like, construction of; framework.—Cantilever wings, braced against torsional deflection, have spaced spars, composed of upper and lower narrow booms b1 b2, c1 c2 and webs b3, c3, stayed apart at intervals by compression ribs d and thus divided into rectangular or trapezoidal sections from the root to the outer end, and braced by triangular tension bracing members e1 e2, e3 e4, f1 f2, f3 f4, having their bases on the upper and lower booms and the apices of the bracing members on the upper booms of different spars connected together and also the apices of bracing members on the lower booms connected together to form opposed pyramids e1. . e4 and f1 . . f4, the apices of one pyramid being stayed apart from the apices of the opposite pyramid by means of a strut g. Alternatively an intermediate spar may replace the struts g, the apices of the pyramids being located on its booms. Similarly more than three spars may be braced together by tension members forming a link 14, has a lateral extension 4 coupled by a link 5 to a bell‐crank lever 6 which is connected by cables 10, 11 to the brakes on the two sides of the machine. Two additional cables 18, 19 extend from the brakes to the lower end of the lever 15. The cables are normally slack and the slack is taken up sufficiently to apply the brakes only when the control lever 1 is moved to extreme positions. A modification is described in which the cables 10, 11 are connected directly to the lower end of the control column 1. Hydraulically or electrically applied brakes may be used instead of the cable‐actuated brakes shown.

The purpose of this paper is to study the preload range of tendon-driven manipulator and the relationship between preload and damping. The flexible joint manipulator (FJM) with joint flexibility is safer than traditional rigid manipulators. A FJM having an elastic tendon is called an elastic tendon-driven manipulator (ETDM) and has the advantages of being driven by a cable and having a more flexible joint. However, the elastic tendon introduces greater residual vibration, which makes the control of the manipulator more difficult. Accurate dynamic modeling is effective in solving this problem.

The present paper derives the relationship between the preload of the ETDM and the friction moment through the analysis of the forces of cables and pulleys. A dynamic model dominated by Coulomb damping is established.

The linear relationship between a decrease in the damping moment of the system and an increase in the ETDM preload is verified by mechanics analysis and experiment, and a curve of the relationship is obtained. This study provides a reference for the selection of ETDM preload.

The method to identify ETDM damping by vibration attenuation experiments is proposed, which is helpful to obtain a more accurate dynamic model of the system and to achieve accurate control and residual vibration suppression of ETDM.

This paper presents a new method for deploying RoboCrane‐type cable robots, without the need for fixed rigid cable support points. That is, the system provides its own deployable mobile overhead support points.

This paper presents a new RoboCrane support concept based on rigid members, cable actuation, and cable suspension. It is self‐contained and provides mobility for the required six overhead cable connections, thus extending the workspace of the existing RoboCrane. The paper presents the RoboCrane support concept overview, followed by kinematics and statics analysis, plus a case study of a specific design.

Design for kinematic horizontality, workspace, and statics are competing so the designer must make tradeoffs for the best system performance according to specific design needs.

Since the support system plus RoboCrane are both cable‐suspended robots, there are limitations in the pseudostatic workspace, i.e. since the cables can only exert tension and cannot push, the motion range is limited.

Specific system design and deployment is still remaining work – practical issues such as outriggers for moment and tipping resistance, easy portability, control of the mast from the ground, and safety must be solved in the future.

Enables RoboCrane applications in many more arenas, such as automated construction, where rigid overhead cable support points are simply unavailable.

An aircraft wing is provided with two flaps normally nested one above the other, each flap being adapted for alteration of angle of incidence relative to the main wing and at least one being supported on travelling mechanism adapted to displace it rearwardly relative to the main wing and to the other flap. In one form, Fig. 6, a split flap 3 is pivotally mounted at 2 below an extension flap 5 which is carried by mechanism comprising a hydraulic or screw jack of which the plunger 6 carries a pivot 7 for a lever 8 rigid with ilap S. To the end of plunger 6 is pivoted one of a pair of toggle links 9, 10 of which the other is pivoted to ilap 5. The centre pivot 11 of the links is connected to a cable 12 passing through a fixed eye 13 in the wing and provided with a stop 12? such that after a certain rearward travel of the flap the cable is held to cause the toggle links to open and move the flap downward. A spring 14 serves to take up slack in the cable in the nested position of the Ilap. Spring means may be used to return the flap to neutral on the return stroke. The control mechanism of (lap 3 may be so interconnected with that of flap 5 or may be such that the flap moves slightly downward when flap 5 is operated, in order to give the latter free passage. Plunger 6 may carry cam means serving to depress flap 3 and may be guided in rollers. In a modification, Fig. 8, the Haps are extended by lazy‐tongs linkage having upper pivots 20, lower pivots 21, and intermediate pivots 22 disposed nearer to the lower than to the upper pivots so that rearward movement of the aftermost links is accompanied by downward movement. Various curved paths may be obtained by asymmetrical arrangement of these pivots. Links 23?, 23B carry pivot pins 23C, 23D. A flap 24 is pivoted on pin 23C and is formed with a cam slot 24A engaged by pin 23D. A second (lap 25 which is adapted to nest below ilap 24 is similarly mounted on links 23E, 23F. Extension of the linkage is by jack means of which the centre line is shown at 26. When fully extended the chord of the first flap is at an angle of 18J deg. to the chord of the wing and that of the second Hap is at 22 deg. to that of the first.